Sustainable Surface Modification of Polyetheretherketone (PEEK) Implants by Hydroxyapatite/Silica Coating—An In Vivo Animal Study

Abstract

Polyetheretherketone (PEEK) has the potential to overcome some of the disadvantages of titanium interbody implants in anterior cervical and discectomy and fusion (ACDF). However, PEEK shows an inferior biological behavior regarding osseointegration and bioactivity. Therefore, the aim of the study was to create a bioactive surface coating on PEEK implants with a unique nanopore structure enabling the generation of a long-lasting interfacial composite layer between coating material and implant. Seventy-two PEEK implants—each thirty-six pure PEEK implants (PI) and thirty-six PEEK implants with a sprayed coating consisting of nanocrystalline hydroxyapatite (ncHA) embedded in a silica matrix and interfacial composite layer (SPI)—were inserted in the femoral condyles of adult rats using a split-side model. After 2, 4 and 8 weeks, the femur bones were harvested. Half of the femur bones were used in histological and histomorphometrical analyses. Additionally, pull-out tests were performed in the second half. Postoperative healing was uneventful for all animals, and no postoperative complications were observed. Considerable crestal and medullary bone remodeling could be found around all implants, with faster bone formation around the SPI and fewer regions with fibrous tissue barriers between implant and bone. Histomorphometrical analyses showed a higher bone to implant contact (BIC) in SPI after 4 and 8 weeks (p < 0.05). Pull-out tests revealed higher pull-out forces in SPI at all time points (p < 0.01). The presented findings demonstrate that a combination of a bioactive coating and the permanent chemical and structural modified interfacial composite layer can improve bone formation at the implant surface by creating a sustainable bone-implant interface. This might be a promising way to overcome the bioinert surface property of PEEK-based implants.

Implant Materials for Anterior Column Reconstruction of Cervical Spine Tumor

“… 32 Frankenberger et al . 33 found that the HA/SiO2‐based bioactive coating with interfacial composites on PEEK implants provided a lasting bone‐implant interface, and may be conducive to improving the property of bioinert surface of PEEK‐based implants. Addai et al .…”

“…Therefore, these materials are usually used as surface coatings to improve the properties of PEEK, such as osseointegration and bioactivity. 32 Frankenberger et al 33 found that the HA/SiO2-based bioactive coating with interfacial composites on PEEK implants provided a lasting bone-implant interface, and may be conducive to improving the property of bioinert surface of PEEK-based implants. Addai et al 34 successfully prepared the reduced graphene oxide hydroxyapatite composite coating, significantly improving the hydrophilicity and bioactivity of PEEK.…”

Customized Barrier Membrane (Titanium Alloy, Poly Ether-Ether Ketone and Unsintered Hydroxyapatite/Poly-l-Lactide) for Guided Bone Regeneration

“…In recent years, PEEK implants have gone through three development phases: 1) mechanical property enhancement; 2) cytocompatibility and osteogenic ability enhancement; and 3) osseointegration and anti-inflammatory enhancement ( Gu et al, 2020 ). Improvement in PEEK properties is usually achieved through surface modification ( Frankenberger et al, 2021 ; Mehdizadeh Omrani et al, 2021 ; Jiang et al, 2022 ) and blending modification ( Ma et al, 2020 ; Ren et al, 2020 ; Hu et al, 2022 ). Waser-Althaus et al used oxygen and ammonia plasma to modify PEEK surfaces and enhance their hydrophilicity and protein adsorption capacity.…”

Piezoelectric Polarization Enhanced Photogenerated Carrier Separation of Bi2S3–BaTiO3 Nanostructure-Based Photoelectric Poly-L-lactic Acid Scaffold for Stimulating Cell Growth

“…The repair of bone defects caused by trauma, tumors, and osteoarthritis was a prevalent conundrum in the medical field. , According to the investigation, surpass 2.2 million bone transplanted surgeries were performed annually worldwide to repair bone defects . Bone defects could trigger grievous hazards to patients, such as bone nonconnection, delayed healing, and functional disorders. − Electrical stimulation was widely believed to be beneficial to promote bone repair since it could stimulate the release of growth factors, boost cell proliferation, and fortify extracellular matrix production to enhance osteoblast activity. , Currently, although electrical stimulation is frequently achieved through implanted electrodes, it usually requires complex external wiring and onerous power supply, which will undoubtedly cause discomfort and even secondary damage to patients. , Accordingly, it is urgent to construct a safe and efficient self-powered electrical stimulation strategy for promoting bone regeneration.…”